After battling with this for an hour, i though this might help anyone with the same problem. I am not entirely sure how this fixed the problem, but it did.
After updating the NuGet package manager, i created a simple Asp.NET Core 1.0 project and tried to compile it. This resulted in multiple errors that looked like this:
“NuGet restore failed. Response status code does not indicate success: 404… “
I added another API endpoint for NuGet to search for packages, and it did the trick.
The URL is: https://api.nuget.org/v3/index.json
NOTE: If you are using any private repositories that are currently unavailable within your network, then you might need to disable them in Visual Studio NuGet feeds settings.
As i understand, this is the URL you should use for NuGet v3 and Visual Studio 2015.
I updated to NuGet v3 but did not add the additional repository URL.